You talk like level design can't be used to benefit the narrative, or even the emotional pull of the narrative. A huge part of why the Resident Evil franchise is so engaging to play, is picking up on the tiny enviromental clues in order to piece together the specifics of what is happening. This player led discovery is core to the gameplay loop of Resident Evil, so world building and gameplay are intricately linked.
Complaints like geographical inconsistancies are of course meaningless, but not because the design is purely slave to the gameplay. From time to time, designing a location or setpiece realistically makes it harder to actually believe in it. That's because small details, while technically correct in the story, are inconsistant with the pace and emotion of the player experience, and are thus distracting.
There are bathrooms in RE1 because the player is meant to believe it is a mansion, a lived in space. They then slowly piece together that the mansion is more than a little odd, through the rooms they unlock and the puzzles they solve, eventually coming to the discovery that the mansion itself is a facade for a hidden laboratory.
RE2 does not have bathrooms, because the place you explore is an inconsistant mess of a converted museum. There are extravagant puzzles and ornate halls, but also plenty of rooms that are gutted out and made utterly mundane with desks and lockers. The lack of basic ammenities communicates how inconvenient and ramshackle the RPD is as a facility, almost as if parts of it feel corrupted somehow. And this helps set up the characterisation of Chief Irons, allowing the player to get a handle on their personality, purely through the level design and a couple of short notes.
